Analyzing the ebb and flow of traffic to skin sites over the past five years, I've arrived at some interesting truisms regarding our prurient online behavior. For example, when looking at porn visits by day of week, without fail, Fridays rank as the most popular day to visit porn sites, while Sunday, traditionally the day of rest or Christian Sabbath, is the least busy day of the week. As we pull our winter coats out of the closet, temperature also affects visits to porn sites. The colder the region, the more adult entertainment visits per capita.

When we think porn, we often jump to the conclusion that this is a male-dominated category. One of the more interesting trends is the increase in female visits to the category. As of the first week of November 2009, more than 30 percent of all porn visitors in the United States were female. But when we look at habits of women versus men, the difference between the sexes couldn't be clearer.

While men visit free adult video or "tube" sites—sites that provide something visual in the form of entertainment—women have an entirely different interest. One of the persistent differences between men and women (both online, as well offline) is that men tend to have stronger interest in visual content, while women are more likely to consume content in text.